Rivers unlikely to challenge Brees

SAN DIEGO -- Here are five observations on the San Diego Chargers, based on their Aug. 8 practice:

1. In his first training camp, backup quarterback Philip Rivers is having some growing pains. Though Rivers is known for his accuracy, he is having good days and bad days in camp. He is throwing too many wobbly passes, and often missing his target.

"Some of it is being rusty," Rivers said. "I'm excited about my progress, but yeah, I've made some mistakes and had some tough days."